Okay, I admit it. My work-in-progress contains a rubber duck moment. Codename NRT, the novel has a very short timeframe. There is no chance to get to know the characters before they are plunged into the mystery on page 1. Thumbnails must suffice until enough pages have been peppered with hints and clues from their mode of dress, their speech, the background information they let free with and straight prose description. I’ve avoided ‘plot bricks’ as far as I can; those clumsy speeches where someone says ‘But Sally, you are my sister!’

Key pieces of a character’s history should fall out in natural dialogue, challenge and argument. We as readers are new acquaintances of these people, and within the story come the subtle enquiries new acquaintances make – are you married, do you have any children? If not asked directly people often go for the opening, ‘So you actually worked for NASA?’ This explains the character’s hint of a Transatlantic accent and allows a lead in to how she ended up in the USA and why she came back. We already know she’s scarily smart. Police procedurals are allowed to be more blunt: ‘Exactly what is your relationship to the deceased?’

Drink is great. In their cups, people often spill their life story. Not always in a coherent fashion, not always honestly and rarely in chronological order but it tumbles out. ‘I was drinking this stuff when I met him in that night club.’

A point came in NRT where there were still many unanswered questions about character A. She keeps her own council, we never meet her friends or her family or her workmates; all these are usual vehicles for allowing us to expand our understanding of the person underneath. We often see a character at work, we see the interaction with Mum/Sister/Boyfriend and they naturally ask about her day, or remind her of some upcoming appointment. Not so with A. So I needed a rubber duck moment to allow her to open up, drop enough facts about her past to allow us to piece together the last clues to her motivation.

The classic scene has our grizzled hero explain that the reason he’s hard-bitten and avoids company is because his father threw away his rubber duck when he was six. He never trusted anyone else again, never wanted to be a father himself, never cared for family. Movies often use this vehicle, some well, some clumsily. Unlike novels, a thriller only has moments to create thumbnail characters. Female thriller heroes/villains/femmes fatales often need such a moment to explain why their behaviour is abberant – an abusive relationship, a lost child, an ugly assault, bloody men obstructing their path to the top. By their nature males can often get away with violent, obsessive or antisocial behaviour without needing deep psychological analysis of how they got there.

So two of my characters come together in bar, tired, jaded at the end of their tether. J is chatty, needing company. She gets very little out of A beyond single-line responses, but is enough for us to finally understand A’s life choices.

‘Do you want to call your people?’

‘I don’t have any people.’

‘Mum?’

‘Died having my sister.’

‘So you’ve a sister?’

‘She died too. It was very Victorian.’

Mother, sister and next her father are dealt with in a few words each. We already know why she quit NASA and are getting to understand how she came to work there in the first place. It is not purely a rubber duck moment though; by using the past, I lead into hints and undercurrents of what is to come. This woman has no family and no ties; but does she have a plan?